Themis

The Themis programme is an ongoing European Space Agency programme that is developing a prototype reusable rocket first stage and plans to conduct demonstration flights. The prototype rocket will also be called Themis, with flights slated to begin as early as 2023. Context Themis is expected to provide valuable information on the economic value of reusability for the European government space program and develop technologies for potential use on future European launch vehicles. Themis will be powered by the ESA's Prometheus rocket engine. Two possible landing sites have been mentioned in discussions surrounding the project: The former Diamant launch complex, which will be used for the flight testing phase; The Ariane 5 launch complex, which will become available after the transition from the Ariane 5 to the next-generation Ariane 6.